The invention relates to a microscope including an illumination device. More specifically, the invention relates to a microscope in which the intensity and color temperature of light is regulated.
German Offenlegungsschrift 2,757,543 discloses an illumination device for a microscope. Proceeding from a light source, this illumination device exhibits a condenser system and an annularly curved light guide. Between the condenser system and the light guide there is disposed a filter device, which exhibits, on a carrier, a plurality of individual filters disposed side by side.
By manual movement of this device in the illumination beam path, the illumination light is matched to a specified color temperature in accordance with the filter brought into the working position.
The measurement of the color temperature takes place by a separate measuring system which is disposed on the tube of the microscope. However, for this purpose it is necessary to remove the existing accessory devices, such as for example, a photographic camera, and to replace them by the color temperature measurement system. A particular disadvantage in this case is the awkward incorporation of the color temperature measurement system and the danger, associated therewith, of having to adjust once again the microscope which has already been adjusted. Furthermore, such an arrangement is affected by the disadvantage that the intensity of illumination in the microscope is altered by the regulation of the color temperature. A matching of the intensity of illumination by regulating the lamp voltage is not possible in this case, since an altered lamp voltage alters the color temperature of the illumination light.
Furthermore, German Offenlegungsschrift 3,627,354 discloses a microphotographic device as a separate accessory of a microscope. This device exhibits a photographic camera, a light measurement device as well as a color temperature measurement device. The color temperature measurement device includes two photodiodes with an upstream blue or red filter. Both photodiodes are acted upon simultaneously by light by means of an appropriate optical system. The light measurement device as well as the photodiodes are connected to a control device via electrical conductors. By inserting a deflecting mirror into the measurement beam path, the light measurement device or the color temperature measurement device may selectively be activated. This microphotographic device has proved to be effective in practice, but does not include any device for matching and regulating the color temperature of the microscope light.